1. Field of the Invention
The invention relates to a method and apparatus to install pipe string and control lines secured to the pipe string in a drilled borehole. More specifically, the invention relates to a method and apparatus to position control lines to facilitate securing control lines to a string of pipe as the pipe string is being made-up and run into a borehole.
2. Background of the Related Art
A pipe string is generally installed in a drilled borehole by lowering a distal end of a pipe segment or a pipe string into the borehole, supporting the pipe segment or the pipe string from its proximal end using a pipe engaging apparatus, threadably coupling a pipe segment to the proximal end of the pipe string above the rig floor, and again lowering the lengthened pipe string into the borehole. This process is repeated until the pipe string achieves the desired length, after which it may be positioned within a targeted interval of the drilled borehole and cemented into the borehole.
The pipe string is generally supported within the borehole from its proximal end using a stationary spider or a collar load support (CLS) landing spear at or adjacent to the rig floor so that an additional pipe segment may be coupled to the proximal end of the pipe string to lengthen the pipe string. A vertically movable elevator assembly, such as a string elevator or casing running tool (CRT), may be movably suspended above the spider or CLS landing spear to engage and support the pipe string from its new proximal end (at the proximal end of the newly added pipe segment) to unload the spider or CLS landing spear. After the spider or CLS landing spear is disengaged from the pipe string, the pipe string may be lowered into the borehole by lowering the elevator assembly, and the spider or CLS landing spear may be reengaged just under the new proximal end of the pipe string.
The spider or CLS landing spear is supported by a rig in a manner that distributes the load of the pipe string to structural components in or under the rig floor. Alternately, when the load of the pipe string is supported by the elevator assembly, the load of the pipe string is distributed to structural components of the rig through a block, a draw works and a derrick to unload the spider or CLS landing spear so that it can be disengaged and opened to permit enlarged portions of the pipe string, such as pipe joints, to pass through the spider or CLS landing spear into the borehole. Specifically, to transfer the load of the pipe string from the elevator assembly back to the spider, the slips of the spider must engage and grip the exterior surface of the pipe string so that the pipe string can be supported by the spider and then released by the elevator assembly. Similarly, to transfer the load of the pipe string from the elevator assembly to a CLS landing spear, the halves of the CLS landing spear must close on and surround the exterior surface of the pipe string just below a pipe joint so that the pipe string can be supported by the CLS landing spear and then released by the elevator assembly.
Oil and/or gas wells may be equipped with control lines for electrically, fluidically or optically linking various downhole devices to the surface. For example, control lines may be used to receive data from downhole instruments and to selectively operate, from the surface, downhole devices such as valves, switches, sensors, relays or other devices. One use of control lines may be to open, close or adjust downhole valves in order to selectively produce or isolate formations penetrated by the borehole. A control line may also transmit data gathered downhole to the surface, and control lines may transmit commands from the surface to downhole devices.
Control lines may comprise conductive wires or cables for electrically controlling downhole devices, fibers for optically controlling downhole devices, or small-diameter tubing for fluidically (e.g., hydraulically or pneumatically) controlling downhole devices. Control lines are generally of a small diameter compared to the diameter of the pipe string to which they may be secured, and are generally between 0.5 and 6 cm. in diameter. Control lines may be generally aligned along the length of a portion of the outer surface of a pipe string, generally parallel to the center axis of the bore of the pipe string, and secured to the pipe string using clamps, ties, straps, etc. Although pipe strings generally comprise a plurality of pipe segments coupled together at pipe joints, a control line is generally continuous or has few joints along its length in order to eliminate or minimize couplings along the control line. Control lines may be stored on a reel that may be brought to the rig and unreeled as the control line is secured to the pipe string and installed in the borehole.
A pipe string is generally made-up and run into the borehole using a spider supported in or on a rig floor. The spider may comprise a tapered bowl that movably receives pipe slips that converge to engage and grip the pipe string, and retract to release the pipe string. Alternately, a collar load support (CLS) landing spear may comprise a pair of halves that can be closed around the pipe string to support a load transfer sleeve that engages an upper collar of the pipe string, as disclosed in U.S. Pat. No. 6,651,737, a patent that is assigned to and owned by the owner of the patent rights related to this disclosure. An elevator assembly, such as a string elevator or a casing running tool (CRT), is generally vertically movable above the spider or the CLS landing spear, and may be used to engage and movably support the pipe string so that the pipe string can be released at the spider or CLS landing spear, and so that the lengthened pipe string can be lowered further into the borehole. Whether a spider or a CLS landing spear is used to support the pipe string, during this critical “hand-off” step, the one or more control lines must be positioned and protected so that they will not become damaged. A control line secured to a pipe string is subject to being damaged and rendered useless if it is pinched or crushed between the tapered bowl and the slips of a spider, two adjacent slips of a spider, the halves of a CLS landing spear, or the pipe string and another structure. For example, but not by way of limitation, a control line may be damaged if it is pinched between the pipe string and the pipe slips that may be movably received within the tapered bowl of a spider to engage and grip the pipe string. Similarly, a control line may be damaged if it is crushed between the pipe string and the wall of the borehole as the pipe string is lowered into the borehole. If a control line is pinched or crushed, it may be necessary to remove the entire pipe string from the borehole in order to remove and replace the damaged control line, thereby resulting in a substantial loss of valuable rig time.
The control line may be secured to the pipe string using a clamp, tie, strap, band or other device. For example, but not by way of limitation, a protective clamp may be applied to secure the control line to the pipe string and also to protect the control line at critical positions along the pipe string, such as at pipe joints. Some control line clamps comprise an elongate guard member, shaped to cover and shield a portion of the control line adjacent to a pipe joint, and end portions that may couple to the guard member to secure the guard member to the pipe string and to secure the control line to the pipe string.
When running one or more control lines into a borehole along with the pipe string, it is important that the pipe slips of the spider engage and grip the pipe string in a manner that prevents crushing or damaging the control line while making up the pipe string. It is advantageous if the control lines can be positioned out of the zone of operation of the spider, or the CLS landing spear, when the spider is engaged to grip, or the CLS landing spear is closed to support, the pipe string. A control line positioning apparatus, such as a pivotable arm, may be used to position a portion of one or more control lines to prevent exposure of the control lines to crushing or pinching by the spider or by the CLS landing spear. Optionally, a rig floor, a shock table, the tapered bowl of a spider, or some other structure to support the spider or the CLS landing spear may comprise a groove, bay or recess into which the control lines can be positioned using the control line positioning arm to protect the control lines during operation of the spider or the CLS landing spear. After the load of the pipe string is transferred to the elevator assembly to unload the spider or the CLS landing spear, the control line positioning arm may then be actuated to reposition the portion of the control lines from the groove, bay or recess to a raised position proximal the pipe string but above the disengaged spider or the opened CLS landing spear so that a portion of the length of the control lines lie along the exterior surface of the pipe string to facilitate application of a clamp.
One or more reels on which control lines are stored may be disposed on or near the rig floor, and unreeled to supply control lines to the control line positioning apparatus that is one the rig floor proximate the pipe string. In order to prevent a hazard to personnel and equipment on the rig floor, the control lines may be directed overhead to one or more guide members, such as a sheave or roller, supported above the rig floor. For example, control lines may be fed from a reel, and about one or more guide members supported from the derrick and redirected toward the control line positioning apparatus on the rig floor. Alternately, the control lines may be routed through a radially more direct path to the control line positioning apparatus and to the pipe string along a path that is substantially radial to the axis of the pipe string and spaced-apart from the rig floor, but this arrangement is more likely to interfere with rig floor activities and equipment.
What is needed is a method of safely securing control lines to a pipe string as the pipe string is being made up and run into a well. What is needed is a method and an apparatus that shelters control lines and prevents damage to control lines being secured to a pipe string and installed in a borehole with the pipe string. What is needed is a method and apparatus to reliably position control lines and to provide a reliable control line feed to a control line positioning device, and to prevent the control lines from entering the operating zone of a spider or a CLS landing spear unless the spider or CLS spider is disabled from closing around a pipe string. What is needed is a method and an apparatus to deliver a control line feed to a control line positioning device that routes the control lines along a path that will not interfere with personnel or equipment on the rig floor.